Bleaching animal fibers



Patented Dec. 5, 1933 Umreo STATES 1,987,710 BLEACHING ANIMIAL FIBERSJose! Miiller,

Austria, assignor,

Weissenstcin above the Drau, by mesne assignments, to

E. I. du Pont de Nemours and Company, a corporation of Delaware NoDrawing. Application January 24, 1931,

Serial No. 511,109, and in Austria. January 31,

7 Claim.

This invention relates to bleaching animal fibers, such as hair,feathers, wool, and the like, with baths containing percompounds orcompounds containing active oxygen. More particularly, the inventionrelates to bleaching stumps, clippings, or dead ends, of rabbit hairwith solutions of compounds containing active oxygen, especiallyhydrogen peroxide.

Heretofore, bleaching of animal fibers, es-

10 pecially stumps of rabbit hair, has not been satisfactory. When usingordinary weakly alkaline hydrogen peroxide baths, a poor color andnon-uniform hues were obtained. Furtheremore, the loss of unusedhydrogen peroxide by previous methods was high. The chief difidcultieswhich have been encountered in bleaching rabbit hair have been dueprincipally to the fact that the hair has previously been treated withnitric acid or mercuric nitrate or other nitrates for the purpose offelting the hair. Mercuric nitrate has chiefly been used for thispurpose. When the treated or carroted hair is brought into contact withthe hydrogen peroxide, especially if the carroting has been done with amercury salt, various decomposition reactions occur which cause the bathto become very inemcient and produce a bad color. Also, the alkalinityof the baths previously used effected the property of the hair in anunsatisfactory manner.

The object of this invention is an improved bleach bath containingactive oxygen compounds and its use in bleaching animal fiber,especially carroted rabbit hair and the like. A further object is a newhydrogen peroxide bleach bath and its use in bleaching animal fibers,which bath will bleach uniformly a comparatively low consumption ofactive oxygen for the amount of bleaching action obtained,

4.0 and which will give brighter hues than the usual alkaline solutionsso used, to which ammonia and water glass and the like has been added. Afurther object of the invention is to retain the satisfactory quality ofthe material being treated, and in no case producing a hard feel undertouch, such as that caused by alkaline baths.

It has now been found that the above objects, and others which may beevident from the description of my invention given below, can beattained by the use of a solution containing active oxygen, especiallyhydrogen peroxide, which is acid in reaction and which contains adissolved aluminum salt. It has been found,

for example, that a very good bleaching action and thoroughly with isobtained upon stumps of rabbit hairs, which have been carroted, by theuse of an acid hydrogen peroxide solution to which has been addedpotassium alum. The following examples will serve to illustrate myinvention.

1. Dark rabbit hair stumps for use in making hats were put into ableaching solution which contained 1 per cent hydrogen peroxide and 1per cent potassium alum. The reaction of this solution was weakly acid.The material 5 was treated in this bath for twenty-four hours at 30 C.at the end of which time it had been made very much lighter in colorwithout suffering any damage in the quality. The soft feel of thematerial remained just as it was before m treating. The color effect wasuniform and only 10 to 20% of the original hydrogen peroxide was used.

When the raw material of this example was bleached in the usual alkalinebath, the bleach- ":5 ing effect was not nearly so good and the feel ofthe material was hard. In most cases, the samples in such a bath had avery poor color. Furthermore, the amount of peroxide necessary, orused,was considerably higher than that an used in the above example.

2. Dark bed feathers were put into a bath containing 5 per cent ofhydrogen peroxide in addition to 0.25% of alum and 0.25% ofsodiumaluminum chloride. The solution reacted weake5 ly acid. Aftertreating the material twenty-four hours at 30 C. it was much brighter incolor and 'had not experienced any deterioration of quality.

If one bleaches the material of this example in -the usual alkalinesolution, the amount of active oxygen compound will need to be about 50%higher and the bleach will be no better. An alkaline bath used underthese conditions also gives indications of having been destroyed.

The above described acid bleach baths containing dissolved aluminumsalts have been used for bleaching of all kinds of human hair as well aswool yarn.- It has been found that the quality of these products is notdamaged, 190 whereas the properties of the same material, when employingthe usual alkaline hydrogen peroxide baths, is always harmed to a markeddegree. Although in some instances, the extent of the bleach may beweaker than is the case when using an alkaline bleach, nevertheless, ifone uses the baths of this invention a of bleached mateconsiderablybetter quality rial is obtained.

Instead of potassium alum, other soluble aluminum salts such as aluminumchloride, aluminum sulphate, sodium alum, sodium-aluminum chloride andother complex salts of aluno separation occurs. Furthermore, the presentinvention, describing the use of soluble compounds of aluminum, differsfundamentally from that method described in Austrian Patent #65,?34,wherein insoluble compounds of aluminum or tin are added to the bleachbath.

What I claim is:

2. Process of bleaching animal fibers which comprises treating thematerial to be bleached in an acid solution containing a solublealuminum salt and hydrogen peroxide.

4. Process of which 5. Process of bleaching rabbit hairpreviouslycarroted with mercury compound which comprises treating the hair in'anacid solution containing dissolved potassium alum and hydrogen 6. Ableach bath having an acid reaction and containing a soluble aluminumsalt and a compound which is capable of liberating active oxygen.

l. A bleach bath having an acid reaction and containing a dissolved alumand hydrogen peroxide.

JOSEF MUILER.

